Multiscale Particle-Continuum Simulations of Hypersonic Flow over a Planetary Probe
Multiscale Particle-Continuum Simulations of Hypersonic Flow over a Planetary Probe
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DOI：
10.2514/1.37319
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发表时间：
2008-11
影响因子：
1.6
通讯作者：
T. Schwartzentruber;Leonardo C. Scalabrin;I. Boyd
中科院分区：
文献类型：
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作者：
T. Schwartzentruber;Leonardo C. Scalabrin;I. Boyd
采用模块化粒子-连续介质数值方法，模拟了70°钝锥行星探测器在各种定常高超声速条件下的绕流。所研究的条件对应于全球Knudsen数较低的流动，其中高超声速导致必须模拟的大范围的时间和空间尺度。模块化粒子-连续体算法松散地耦合了直接模拟蒙特卡罗方法和Navier-Stokes方法，这两种方法分别在非平衡区和连续区运行。此外，粒子区域和连续区域具有不同的网格密度，并使用不同大小的时间步长进行更新。模拟结果表明，模块粒子连续模拟能够较高精度地再现探头表面的升温速率、速度滑移和热不平衡，以及直接模拟蒙特卡罗方法所预测的流场特性。这种混合粒子-连续介质方法首次被证明在获得高精度的同时，与纯粒子模拟相比，所需的计算时间和内存减少了一个数量级。在稠密前体流中，模化粒子-连续介质模拟结果与N-S模拟和实验测量结果吻合较好。在行星探测器的稀薄尾迹中，模粒子连续谱结果与实验测量结果相比，比Navier-Stokes模拟更符合。
Amodular particle-continuum numericalmethod is used to simulate the flow over a 70 deg blunted cone planetary probe geometry under various steady-state hypersonic conditions. The conditions studied correspond to low global Knudsen number flow where hypersonic velocities induce a large range of temporal and spatial scales that must be modeled. The modular particle-continuum algorithm loosely couples direct simulation Monte Carlo and Navier– Stokes methods, which operate in nonequilibrium and continuum regions, respectively. In addition, particle and continuum regions have different mesh densities and are updated using different sized time steps. Modular particlecontinuum simulations are shown to reproduce the heating rates, velocity slip, and thermal nonequilibrium on the probe surface, as well as the flowfield properties predicted by the direct simulation Monte Carlo method with high accuracy. For the first time, such a hybrid particle-continuum method is shown to achieve high accuracy while achieving an order ofmagnitude decrease in required computational time andmemory compared with pure particle simulation. The modular particle-continuum simulations agree well with Navier–Stokes simulations and experimental measurements in the dense forebody flow. In the rarefied wake of the planetary probe, the modular particle-continuum results are in better agreement with experimental measurements than Navier–Stokes simulations.